Weight adjustment by means of a ramp

ABSTRACT

A weight adjuster on a weight station which has a support frame on which a rotatably mounted guide frame is attached which has rails on which the weight can be moved in the longitudinal direction by means of pulleys or sliding elements, and the angle of the guide frame is continuously adjustable by means of an actuator means and therefore effects a change in the load on the rope. The rope can supply electrical power, and a training program can be optimized by means of buttons, a force sensor, a rotational-speed sensor, a vibration generator and the controller.

TECHNICAL FIELD

The invention is based on a device on an exercise machine forcontinuously adjusting therewith a training weight by means of anactuator means and for enabling, if needed, a load increase or decreaseby pressing a button or automatically during the training exercise,according to the preamble of the first claim.

PRIOR ART

Exercise machines for studios or for home are known, wherein in mostcases, a metal weight guided on rods can be vertically lifted or loweredwith rope pulls and pulleys, and the ropes can be guided in differentdirections in order to keep the body musculature such as back muscles,arm muscles, abdominal muscles leg muscles and also smaller musclegroups under muscle tension in any angular position in order tostrengthen the musculature and to improve the cardiovascular system. Inorder to maintain a constant force on arms and legs during rotationalmovements, systems are known which, by means of an eccentric, keep acertain weight constant over the entire lift or radian measure, asdescribed in the U.S. Pat. No. 3,858,873 or DE 3445104 A1 or DE 197 10132 C1. For a simpler weight adjustment, manual and electromechanicalsystems are known such as, e.g., U.S. Pat. No. 8,016,729 Bs or DE 102006 003 731 A1, or by means of adjusting the load arm in PatentEP1423170 B1.

Also, machines are known which, instead of using weights, generate acertain tension or pressure by means of fluid cylinders, and somecomprise adjustable load settings.

Likewise, weight machines are known which use steel springs or elasticbands.

Furthermore, systems are known in which an electric motor generates thedesired resistance and the motors serve as resistance and as drive,e.g., in order to take a certain weight position or to provide highresistance during slow-speed weight lowering exercises, called negativeexercises, as described in the U.S. Pat. No. 4,635,933.

SUMMARY OF THE INVENTION

The invention is based on a means that can be adjusted in a simplemanner in order to continuously adjust the training load on an exercisemachine electrically or manually, and to adjust the load also during theexercise and, if needed, to be able to also perform slow-speed exercisesand high-intensity exercises, according to the preamble of the firstclaim.

It is standard for fitness and weight machines to use disc-shaped orrectangular weight elements from metal in different weight classes whichare guided on a vertical rod guide and to connect the respective numberof weight stacks to a pull rod by means of a simple pin, wherein thepull rod is attached to a rope which is guided by means of deflectionpulleys and is finally fastened to the barbell handles or pressureplates for leg pressing or to the respective handle bars for backexercises and abdominal exercises.

The trend is towards optimizing the sitting position, i.e., correctposition of the trainee in order to bring the joints of the trainee inalignment with the rotary elements of an exercise or weight machine,i.e., the body joints are to be aligned as accurately as possible withregard to pivot points of the articulated joints of the machine, and thetraining weights are to be included in the optimization, which trainingweights are generated by means of virtual weights in the form ofelectric motors which generate resistance instead of using metalweights.

The desired and found sitting positions and also the weights to belifted are finally transmitted by means of sensors to a controller andare stored there, i.e., the seat height, the distance from the seat tothe machine, and the handle positions or leg pressing plate positionsare often also stored and serve for finding the same body position againwith respect to the weight station for the next training by making thepreviously stored data accessible by means of a chip of the weightstation.

Also, systems are known in which a weight can be electrically moved bymeans of a boom towards or away from the rotary bearing and thereforeform an adjustable lever arm and the displaceable weight effects in thismanner a change in torque, i.e., a changed load on the pull rope, which,due to the curved movement of such a lever arm, forms unequal loads overthe vertical travel, which is hardly professional. Subsequently, theprovided resisting force is finally transmitted by means of a gear and acorresponding gearing ratio to the barbell handles, wherein acorresponding vertical travel has also to be provided for the barbellhandles.

These complicated and expensive constructions are simplified by means ofthe solution disclosed here and therefore can be produced in acost-effective manner. At the same time, they allow for each angularposition or lifting position of the barbell handles or the foot plate toincrease or decrease the weight in situ.

The advantage of this construction is that the fitness machine is basedon the usual weight unit which is vertically stackable and is guided onrods and which is attached to a rope and is guided via deflectionpulleys to the respective training application, but with the fundamentaldifference that all weight elements are always lifted together, but thetotal weight, which is displaceable on a rail, results in a differentload effected by means of the angularly adjustable rail. If, e.g., thetotal weight is 100 kg and it is vertically lifted upwards, the load tobe lifted is 100 kg plus friction; however, if the total weight istheoretically brought in a horizontal position, no load to be lifted canbe felt, only the friction for horizontally moving the total weight canbe felt. Thus, any angle below 90° increases the load to be liftedaccordingly.

In order that the loads to be lifted on a training machine for fitnessor athletic sports are and remain reproducible, which loads show theactual performance level, and also to document a reliable successstatistics, it is advantageous to keep the friction as low as possibleand to allow no stick-slip effects. This requirement can be ideallyimplemented by pulleys. Magnetic suspension and air cushion suspensioncould also be considered; however, this is an application for exercisemachines and as little electrical power as possible should be consumedand, at the same time, little noise should be generated. The wheels canbe covered with a plastic coating in order to effectively reduce thenoise during the movement on the angularly adjustable rail.

Adjusting the ramp is carried out electrically, either with anelectrically operated spindle cylinder, or hydraulically, wherein oilflow and pressure can ultimately also be generated by means of anelectric motor or by means of a motor with pinion and rack or sprocketor the like.

Furthermore, the exercise machine can also be adjusted manually with thesupport of a gas spring which makes the weight “lighter” and which canoptionally also be directly blocked.

A controller having adequate sensors secures the desired preciseposition of the rail and, associated therewith, the load to be generatedfor each application. Also, with the buttons on the barbell handle, theload can be increased or reduced during training by pressing thebuttons, or auto mode can be selected.

An electric cable that transmits power for the orders and data isoptionally integrated in the pull rope and thus, there are no furthercables that hang around or such cables that have to be fixedappropriately.

Actuating the angular position of the weights can also be carried out bymeans of conventional wirelessly operating buttons; however, they arehardly ecological since batteries have to be appropriately disposed andthus are also associated with service costs. An environmentallycompatible version that involves no service costs can be implementedwith piezo buttons which, upon pressing the button, generate enoughelectricity for providing a corresponding radio signal to thecontroller. Apart from manually operating the buttons, the buttons canalso be operated in “automatic” in that an algorithm in the controllerautomates weight increase and decrease.

Moreover, with this technical solution it is also possible to use theweight station as high-intensity training machine, for negativeexercises in that by the same active cylinder that serves for the basicsetting of the training weight, the weight can be sequentially orcontinuously adjusted during training either manually or by means of analgorithm. It is likewise possible to perform high-intensity negativeexercises with electrically operated weight station without physicalweights; however, the electric power consumption is many times highersince always the total weight, this means, full resistance has to begenerated, whereas with the construction described here, the base loadis set once and thereafter only the differential load is generated bymeans of angular adjustment of the rail, similar to a ramp, and thus thecorresponding load is generated. In addition, no jerking can be felt andalso no cogging torque due to the magnetic fields of an electric motoroperating at low rpm and during long standstill periods under load, suchan electric motor can burn out. With this new solution by means of rampadjustment, it is possible via a simple weight, which has a physicalsize with a constant load acting on the pull rope over the entirelifting travel until a different weight is desired, to provide a newload in a fast and simple manner by pressing a button, which is verymuch appreciated by the trainee.

Due to the elegant rail adjustment by tilting as needed and theassociated change in the load, the trainee does not need a sparringpartner or a personal coach which normally would assist in providingadditional weights or would help during weight lifting.

This is achieved according to the invention by the features of the firstclaim.

The central idea of the invention is that on an exercise or weightmachine having a weight which is attached to a frame and which can bemoved on pulleys on a guided rail, the angle of the guided rail can beadjusted by means of actuator means, and the weight is fastened to arope, and a corresponding exercise means or weight training means isfastened to the other end, and in this manner, the load can becontinuously adjusted or readjusted automatically or manually, whereinthe ramp can be adjusted from vertical to practically horizontal. Theactive cylinder serves for setting the basic load and, at the same time,as a load adjuster for the negative exercises and high-intensityexercises. The pull rope or pull band has an integrated electric powersupply for actuating a button or for displaying the weight, and by meansof these buttons or by means of the remote control buttons, the trainingweight can be individually changed at any time during the course of thetraining.

Further advantageous configurations of the invention arise from thesub-claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereafter, exemplary embodiments of the invention are explained ingreater detail with reference to the drawings. The same elements in thedifferent figures are designated by the same reference signs.

In the figures:

FIG. 1 shows a schematic side view of a weight adjuster on a weightstation, with a guide frame which is rotatably mounted on a supportframe and in which a weight is mounted on rails by means of pulleys andwhich, by means of a hoist via guide pulley and deflection pulleys,guides the weight on a rope to the training application means, and anactuator means on the support frame is connected to the guide frame, andwith buttons which are connected to the pull rope that transmitselectric power and data and are connected to the controller.

FIG. 2 shows a schematic side view of a weight adjuster on a weightstation, with a guide frame which is rotatably mounted on a supportframe and in which a weight is mounted on rails by means of pulleys andwhich, by means of the guide pulley, guides the weight on a rope to thetraining application means, and a gas spring is connected to the guideframe on the support frame and a release cable runs to a console havinga release button provided on an adjusting lever, and a sprocket isattached to the rotatably mounted guide frame, which sprocket is inengagement with a gear rack that is connected to the adjusting lever bymeans of a Bowden cable, and with an angle indicator.

Only those elements are schematically shown that are directly essentialfor understanding the invention.

Ways to Implement the Invention

FIG. 1 shows a schematic side view of a weight adjuster 1 at a weightstation 2 which, on a support frame 3, has a guide frame 4 with a rotarybearing 5 which also carries a guide pulley 6. The guide frame 4 hasrails 7 in which a weight 8 is guided with pulleys 9. The weight 8 on arope 10 is operatively connected to the training means 14 by means of ahoist 11 by means of the hoist pulley 12 and further deflection pulleys13 and is fastened there, wherein buttons 16 with a display 17, whichare connected to the controller 18, are attached on the grip bar 15, andan actuator means 19 on the support frame 3 is connected to the guideframe 4. A force sensor 20, a rotational-speed sensor 21 and a vibrationgenerator 22 are utilized for training optimization.

At weight stations 2, stacked weights which are guided on rods and whichare in operative connection to a pull rope are connected on the oppositeside in each case to a training means, which can be a dumbbell, barbell,foot plate etc. and represent a standard solution. In order to set thestacked weight for training, the pull rope has a perforated rod whichextends into the segmented stacked weights, and each of the weightsegments likewise has a transverse hole which can be connected to theperforated rod by a corresponding pin. The pin carries all stackedweights arranged thereabove and the training weight is adjusted in thismanner. As shown in the U.S. Pat. No. 8,016,729 B2, the desired numberof weight segments can also be connected to one another via gear wheelsand grippers and thus can regulate the training weight.

The inventive solution show a considerably simpler weight adjustment fortraining and is based on the principle of a ramp with an adjustableincline, wherein the displaceable weight 8 is always the same and therequired load for training is achieved by means of the variable inclinedposition of the ramp. A total weight can also be moved as a whole bymeans of a weight attached on a load arm; however, this serves only forsetting the weight relative to the pivot point on the load arm and ininteraction with the engagement point of a pull rope on the load arm,which determines the leverage force, wherein the load arm follows apartial circle, i.e., the load on the rope does not remain constant butforms a sinusoidal shape with regard to the load as a function of theangle or lift.

The inventive solution provides that a constant load acts on the rope 10over the entire lift H with the exception that this can be changedindividually by means of the auto mode or by means of the buttons 16.The weight 8 has smoothly running pulleys 9 which are guided in a guideframe 4 which has rails 7 and serves as a ramp, and the rail 7 has a U-or C-profile or an O-profile or a similar profile which is mounted intubular, concave, convex or flat manner so that the weight 8 is in anycase properly guided in the rail profile of rail 7 and cannot tilttherein, which is also ensured through the centric connection of therope 10 to weight 8. If the rope 10 is pulled, the weight 8 moves like aslide in the central rail or along the rails 7 attached on both sidesand performs a lift H.

By means of the guide frame 4, a ramp incline can be generated in thatan actuator means 19 is attached to said guide frame, which actuatormeans 19 is connected to the support frame 3. The actuator means 19 canbe an electric cylinder or a fluid cylinder or, as shown in FIG. 2, arack means or a pinion or a worm gear and the like and can interact atthe rotary bearing 5 with a motor that is directly attached there.

The ramp incline is detected by means of an angle measurement means orthe like and can be displayed on a display 17 and processed in thecontroller 18.

The guide frame 4 is connected to the support frame 3 by means of therotary bearing 5 and, at the same time, the guide pulley 6 is located atthe rotary bearing 5, which guide pulley serves for keeping the rope 10in the respective running direction. In the basic position, the guideframe 4 hangs vertically from the support frame 3 and in this case, therope 10 runs straight and vertical over the entire distance up to one ofthe deflection pulleys 13. When the actuator means 19 is actuated andthe guide frame 4 swivels upwards, virtually up into the horizontalposition, the rope 10 at the guide pulley 6 passes through an angle ofalmost 90° but enables the weight 8 to continue to slide smoothly in therail 7. The guide pulley 6 is mounted such that the rope 10 pullsparallel to the rail 7, regardless of the ramp position, and alsocentric between the rails 7. By means of the formula for an “inclinedplane” the load acting on the rope can be calculated; however, thefriction values at the guide pulley 6, the deflection pulleys 13 and thepulleys 9 are to be included as well and the whole load can beempirically estimated for different angular positions of the rails 7.Likewise, the effective tensile load on the rope 10 can be effectivelymeasured by a force sensor 20, which can be an inexpensive hangingscale, and in connection with the controller 18, the target value can becorrelated with the actual value by correspondingly extending andretracting the actuator means 19 so that a ramp change is generated andthe angle at the rail 7 changes such that the desired load on the rope10 can be adjusted precisely.

Instead of the pulleys 9, sliding elements can also be used which todayhave very good sliding properties, in particular with the addition ofPTFE or oil-containing incorporations, which is not of centralimportance here, but it has to be ensured that no stick-slip effectoccurs because this could result in a partial intermittences during thelifting movement.

The guiding of the rope 10 illustrated here corresponds to a hoist 11 inthat the rope 10 is fastened to the guide frame 4 and the hoist pulley12 is mounted on the weight 8 and subsequently, the rope 10 is fed pastthe guide roller 6 to the deflection pulleys 13 and is finally fastenedto the training means 14. The advantage is that in this regard, the liftH of the weight 8 is only half with respect to the lift H1 at the rope10 or the grip bar 15. The theoretical disadvantage is that the weight 8has to be double as high, but the benefit that, in turn, the guide frame4 is built correspondingly shorter and thus swings out less farcompensates for the additional weight which can be easily displacedanyway. Specifically for transportation reasons, the weight 8 can befabricated in segments and is then screwed together on site in the rails7 so as to form a unit. In order to save additional space, lead can alsobe used instead of the usual steel since lead has a higher specificweight and therefore reduces the volume of the weight 8. Moreover, theweight can be covered with plastic and thus has a more appealingappearance. Also, the weight adjuster 1 can be enclosed by a cover sothat no adjusting mechanism is visible.

It is optimal if the weight station 2 is equipped with a training cardrecognition so that the trainee only has to insert or place the cardinto recognition device and the machine moves the seat automaticallyinto the stored position, brings the training means 14 in position andalso adjusts the angle S of the guide frame 4 so that the correct“weight” in the form of the correct load is available. In particular,the controller 18 can perform a defined target/actual comparison withthe values of the force sensor 20 and, e.g., can automatically includefriction values that change due to temperature fluctuations or generalwear on the weight adjuster 1. Furthermore, the rope 10, which is a pullrope, can also comprise an integrated data and power supply cable. Thus,buttons 16 can be provided, e.g. on the grip bar 15 so that the traineecan change the load at any time during the training in that theinformation is received by the controller 18 and the latter issues theorder to the actuator means 19 to extend to a greater or lesser extentand thus to generate a greater or smaller angle S at the rail 7, whereincorrelation with the force sensor 20 is also possible at any time. Inaddition, the trainee can set his “weight” that he usually designates assuch and, moreover, can check it on the display 17 which is mounted onthe grip handle 15 or at another place, and can change the load at thetouch of a button, if needed, or can touch a button to leave theoptimization of the training to the automatic mode, which is implementedby an algorithm stored in the controller 18. The algorithm can comprisea program which specifically includes also negative exercises andhigh-intensity exercises, which are not subject matter of thisspecification. However, in order to achieve such optimization, thetraining speed should and can also be considered. For this reason, thelifting speed of the rope 10 is measured by means of a rotational-speedsensor 21 at one of the deflection pulleys 13 or in the form of adistance meter which detects cross lines on the rope 10 and calculatesthe speed in this manner. Thus, a trainee who does not perform theexercises correctly can be notified visually or acoustically in thisregard, or the load is temporarily increased so that the exercises areperformed slowly and as constant as possible.

If a trainee cannot get used to the otherwise so convenient continuousadjustment of the load, artificial steps can be generated by means ofthe controller 18, i.e., each actuation of the button 16 corresponds,for example, to an indicated weight change of 2.5 kg.

The buttons 16 can also be designed as piezo buttons with a radio moduleintegrated therein which are accommodated in the receiver in thecontroller 18 and the controller 18 processes the signal.

The weight adjuster 1 is also suitable for integrating a vibrationgenerator 22 that can be activated in a time-related manner and whichcomprises an unbalance motor which, e.g., at one of the deflectionpulleys 13, causes such a deflection pulley to vibrate so that avibration between 5 and 50 Hz is generated and the vibrations aretransmitted to the rope 10 or the grip bar 15. If the muscle iscontracted, the vibrations generate additional muscle stimulation andthus also contribute to strengthening the musculature. On the otherhand, the trainee can activate the vibration generator 22 withoutperforming his exercises and, e.g., can simply hold the grip handle 15and the vibrations thus effect a positive relaxation of the musculature.

The load guide by means of deflection pulleys 13 at the rope 10 canfinally be mounted to a respective training means 14 such as, e.g., agrip bar 15 or a padded lever for backbends, pelvis lifts or the footplate for leg pressing and further applications which are carried outdirectly or via another transmission or via an eccentric device. Therope 10 can be round or can be implemented as a flat band.

Because the weight adjuster 1 has to move only one weight 8, anindustrial damper 35 can be mounted in a very convenient manner betweenthe weight 8 and the end stop at the guide frame 4 so that even whendropping the rope 10 from great height, the damper 35 absorbs thekinetic energy and thus brings the weight 8 back into the initialposition with only little noise. The damper 35 can be a hydraulic deviceor a specific cellular polyurethane (PUR)-elastomer insert as it isdistributed by BASF under the brand name Cellasto®.

FIG. 2 shows a schematic side view of a weight adjuster 1 at a weightstation 2 as described in FIG. 1, but with the difference that theactuator means 19 between the support frame 3 and the guide frame 4 is ablockable gas spring 23, with the unlocking means 24 and the releaseswitch 25 on the actuator lever 26 which is secured on a console 27.Swiveling out the guide frame 4 is carried out by means of a rack 28with a Bowden cable 29 and a pinion 36 at the rotary bearing 5, ormanually by means of the handle 30, and involves a curved measuring rail31 with the mark 32 and optionally a releasable ratchet lock 33.

Shown here is a simpler variant which can be actuate manually. Becausein many cases it is not readily possible to manually lift the weight 8into the desired ramp position, the blockable gas spring 23 is mountedhere as a force balancing element and behaves similar to gas springs fortrunks of vehicles. The difference is that each position of the angle Sat the guide frame 4 can be locked, and therefore a blockable gas spring23 is used that has an unlocking means 24 that can be a Bowden cable ora hydraulic line. By means of the simple release switch 25 for theBowden cable or the release switch 25 as a hydraulic pressure booster,the blockable gas spring 23 is unlocked, and when releasing the releaseswitch 25, the mechanism locks and the guide frame 4, i.e., the rampposition is secured. Lifting the guide frame 4 is carried out by meansof the handle 30, and by means of a curved measuring rail 31 attached,e.g., on the guide frame 4 and a mark 32 provided on the support frame3, the angle S can be read in this manner or the usual and known valuesare directly indicated in “kg/lbs”.

A slight gain in comfort is achieved if at the console 27, which is asclose as possible to the training means 14, the adjusting lever 26attached next thereto can be actuated—of course, only after pressing therelease switch 25—and a rack 28 is actuated by means of the Bowden cable29, which rack engages with the pinion 36 which is located at the rotarybearing 5 and brings the guide frame 4 into the pivot mode supported bythe gas spring 23. The desired load, which is set via the correspondingramp position, can be fixed in the selected position by actuating theadjusting lever 26 and by means of the position fixations 34. Also, acurved measuring rail 31 can be attached on the console 27 and it can beread from the adjusting lever 26 which value is set or can be set.Standard gas springs 23 are inexpensive, in contrast to blockable gassprings 23. Therefore, there is the alternative to secure the desiredramp position of the guide frame 4 by means of a releasable lock orratchet lock 33.

The spaciously laid Bowden cable 29 shown here or the unlocking means 24can also be laid to be less visible, wherein the laying radius hasalways to be taken into account. The Bowden cable 29 can also be aforce-transmitting shaft that is connected to a spindle drive and bymeans of which significant torques can be transmitted, and this can beused instead of the rack guidance 28 a, rack 28 and pinion 36, in orderto drive a worm gear with the advantage that for gear-related reasons,such a construction already secures the position of an angle S of theguide frame 4, i.e., no further locking means are necessary to securethe angle S.

Of course, the invention is not limited to the exemplary embodimentsshown and described.

1. A weight adjuster, wherein the weight adjuster is connected to aweight station and comprises a support frame on which the guide framewith the rotary bearing and the guide pulley is fastened, and attachedto the guide frame are rails on which the weight is movable, and alsoguided and supported, in the longitudinal direction according to thelift by means of pulleys or sliding elements, and an actuator means isfastened to the guide frame, which actuator means makes the guide framecontinuously adjustable through the angle, and the weight is fastened tothe rope which is fed past or deflected at the guide pulley and isfastened at the other end to the training means and has an anglemeasurement means.
 2. The weight adjuster according to claim 1, whereinthe guide pulley is attached such that the rope pulls parallel to therail and centric between the rails independent of the angular positionof the guide frame.
 3. The weight adjuster according to claim 1, whereinthe rail forms the guide frame and acts as a ramp which can be swiveledfrom a vertical position up to an almost horizontal position.
 4. Theweight adjuster according to claim 1, wherein the rope comprises anintegrated electric power and data cable which can be connected to thebutton, the force sensor, the display and the controller.
 5. The weightadjuster according to claim 1, wherein the guide frame can be adjustedduring training with regard to the angle by means of the buttons orautomatically by means of an algorithm in the controller, and the buttoncan be a piezo button having a radio module.
 6. The weight adjusteraccording to claim 1, wherein the can be detected by a rotary-speedsensor and values are transmitted to the controller.
 7. The weightadjuster according to claim 1, wherein the rope absorbs the frequencygenerated by the vibration generator at the deflection pulley andtransmits it specifically to the training means.
 8. The weight adjusteraccording to claim 1, wherein the training means comprises one of thefollowing elements, which are a grip bar, a pull or push rod, a paddedbar, a padded plate, a foot plate, a strap, a barbell and the like. 9.The weight adjuster according to claim 1, wherein the guide frame can beswiveled hydraulically, electrically or manually by means of theactuator means and can be locked in any position, and the actuator meansis fastened in a rotatably mounted manner to the support frame on theone side and to the guide frame on the other side.
 10. The weightadjuster according to claim 9, wherein the actuator means is a cylinderor a rack with a pinion or a rotary motor with worm gear, and attachedthereto or therein is an angle measuring means or length measuring meanswhich acts electronically or mechanically.
 11. The weight adjusteraccording to claim 1, wherein a hoist serves for elongating the lift bymeans of the hoist pulley which is attached to the weight and effectsthe lift.
 12. The weight adjuster according to claim 1, wherein the ropeis guided at the deflection roller and is optionally attached to a camdisc or an eccentric.
 13. The weight adjuster according to claim 1,wherein the guide frame is supported by a gas spring which can beblocked, or a ratchet lock or a worm gear provides for the locking. 14.The weight adjuster according to claim 1, wherein the weight adjusterhas a damper, and the weight can consist of lead and can be segmentedfor assembly and can have a cover.
 15. The weight adjuster according toclaim 1, wherein a curved measuring rail or a mark is located at theguide frame and curved measuring rail or a mark is located at thesupport frame.